High birth rates and the rise of atheism are behind new statistics showing children in Birmingham are now more likely to be Muslim than Christian, an expert has claimed.

The changing religious beliefs of youngsters in the city has been revealed by data taken from the 2011 census, which has only just been released.

The figures show the number of Muslim children in Birmingham is greater than the number who are Christian for the first time, showing the city’s demographic shift.

Of Birmingham’s 278,623 children, 97,099 were registered as Muslim and 93,828 as Christian in the last census.

There were also 54,343 children who were recorded as following no religion – showing the rising trend of atheism in the country.

Dr David Owen, an expert in census data at the University of Warwick, said: “We’ve seen the ethnic minority population of Birmingham increasing steadily over the years so it’s probably not a surprise that there are now more Muslim children than any other religion. It’s been gradually emerging and it’s not a sudden change.”

High birth rates in Muslim communities and a decline in the number of people identifying themselves as Christian are two reasons for the trend.

He also noted that the Census asks adults to give the religious beliefs of their dependent children, meaning the data does not necessarily reflect the feelings of all children. The form defines dependent children as those aged 15 or below or between 16 and 18 if they are in full-time education and still living at home.

Dr Owen continued: “It is undeniable that the ethnic groups which are typically Muslim tend to have higher birth rates.

“Pakistani and Bangladeshi populations have had higher-than-average birth rates for a long time.

“More recently we have had Muslim migrants from parts of Africa like Somalia and they too have very high birth rates.

“In terms of Christianity, many people still have Christian beliefs but church attendance has fallen dramatically in recent years. That might make people less inclined to put themselves down as Christian on a census form, even if they still believe in a Christian God.”

Dr Owen also suggested that people today may feel more comfortable saying they are atheist.

He said: “People are more willing these days to admit they are not Christian. They feel they can be more honest about it and that nothing bad is going to happen to them if they say they aren’t religious.”

Dr Owen also said that some of the Christian children would be from migrant families, from places like Poland or parts Africa where Christianity often plays a dominant role in everyday life.

As well as Birmingham, Islam is now the dominant religion among children in Leicester, Bradford, Luton, Slough and the London boroughs of Newham, Redbridge and Tower Hamlets.

But the overall pattern across the country, however, shows that Christianity is still the dominant religion in every part of England and Wales.

When taking the religious beliefs of children and adults into account, 41.1 per cent of people in Birmingham say they are Christian and 21.8 per cent say they are Muslim.

No religion was the next most popular option, with 19.3 per cent of the city’s population saying they were atheist.

This compares to the 33.7 per cent of children registered as Christian, 34.7 per cent who were registered as Muslim and 19.7 per cent who had no religion.

In Birmingham, there were also 7,710 children registered as Sikh and 4,377 registered as Hindu. There were 887 children who were registered as “other religion” which could include beliefs such as Paganism, Rastafarianism or Taoism, and the city also has 710 Buddhist and 254 Jewish children.

Religious leaders have stressed the importance of the inter-faith work that goes on in the city.

The Rt Revd David Urquhart, Bishop of Birmingham, said: “I am delighted to live in a city of diverse faiths where all play their part. Inter-faith work strengthens all our faiths and promotes strong and robust communities. We cannot love our neighbour without getting to know our neighbour.”